Tesar 1991.

Methods	Study design: Randomised controlled trial
Participants	Diagnosis: DSM‐III panic disorder with or without limited or extensive phobic avoidance Method of diagnosis: Structured Clinical Interview for DSM‐III‐Upjohn version (SCID‐Up) Age: for alprazolam, M = 32.8, SD = 8.9; for clonazepam M = 30.5, SD = 6.5 Sex: for alprazolam 58 female, 42 male; for clonazepam 58 female, 42 male Location: USA; setting unclear Co‐morbidities: patients with bipolar disorder, OCD, psychosis, dementia, substance abuse or major medical disorders were excluded; a concurrent diagnosis of major depression was permissible as long as it was judged to be secondary to panic disorder Rescue medication: not stated
Interventions	Participants were randomly assigned to either: (1) alprazolam arm (n = 24) Duration: 6 weeks Treatment Protocol: flexible dosage, range = 1 ‐ 10 mg, M = 5.39 SD = 2.89 (2) clonazepam arm (n = 26) Duration: 6 weeks Treatment Protocol: flexible dosage, range = 0.5 ‐ 5 mg, M = 2.5 SD = 0.94 (3) placebo arm (n = 22) Duration: 6 weeks
Outcomes	Time points for assessment: weekly Outcomes: 1. Clinical Global Impression Scale (CGI) 2. Patient Global Assessment (PGI) 3. panic attacks frequency 4. phobias 5. Work and Social Disability Scale 6. Beck Depression Inventory (BDI)
Notes	Date of study: not stated Funding source: sponsored by Upjohn Co. Declarations of interest among the primary researchers: none.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomly".
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "the study drugs were administered in identical capsules according to a standardised but flexible dosing schedule".
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "the study drugs were administered in identical capsules according to a standardised but flexible dosing schedule".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Both endpoint analysis based on LOCF and completers analysis were performed.
Selective reporting (reporting bias)	Low risk	All outcomes were reported.
Other bias	High risk	Supported in part by a grant from the Upjohn Co.; the role of the funder in planning, conducting and writing the study is not discussed.